Eratosthenes 276–195 B.C. This Greek astronomer was the first to measure the size of Earth accurately. He determined that the earth's polar diameter was about 7,850 miles. (In fact, the distance is…
The Milky Way, the galaxy containing our solar system, is about 100,000 light-years in diameter and about 10,000 light-years thick.
Aphelion: see Orbit.
Apogee: see Orbit…
There are eight planets in our solar system including Earth. So far, no life as we know it exists on any planet other than our own. Mercury Mercury, the planet closest to the Sun, has almost no…
There are eight planets in our solar system including Earth. So far, no life as we know it exists on any planet other than our own. Mercury Mercury, the planet closest to the Sun, has almost no…
WARNING!LOOPS IN THE ATMOSPHERESPOTS ON THE SUNNEUTRINOS FROM THE SUNSPACE WEATHERSOLAR ECLIPSEFIND OUT MOREDominating our corner of space is a star we call the Sun. It travels through space…
(Encyclopedia)
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Atmosphere
atmosphere [Gr.,=sphere of air], the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the…
(Encyclopedia) globe, spherical map of the earth (terrestrial globe) or the sky (celestial globe). The terrestrial globe provides the only graphic representation of the areas of the earth without…
Research and provide short answers Directions: Look at the fact pages on Mars and Earth. Then answer the following questions: How long (in years and days) is one Earth year on Mars…
Source: National Aeronautics and Space Administration (NASA) The Moon travels around Earth in an oval orbit at 36,800 kilometers per hour. The Moon does not have an atmosphere, so temperatures…
HOW DO SATELLITES STAY UP IN SPACE? SATELLITE ORBITSFIND OUT MOREA spacecraft that travels in a steady path, or orbit, around Earth is called a satellite. Satellites receive and send on…
